Device for degassing pressure fluids of hydraulic power plants



Dec. 6, 1960 e. CAROL! 6 ,863

DEVICE FOR DEGASSING PRESSURE FLUIDS OF HYDRAULIC POWER PLANTS FiledJan. 30, 1957 United States Patent? DEVICE FOR DEGASSING PRESSURE FLUIDSor HYDRAULIC rowan PLANTS Gerhard Caroli, Klopstockstr. 49, Stuttgart,Germany Filed Jan. 30, 1957, Ser. No. 637,193 (Ilaims priority,application Germany Feb. 1, 1 9 56 6 Claims. (Cl. 60-62) The inventionrelates to a device for degassing pressure fluids of hydraulic powerplants. It is a well known fact that the entering of gases, such as air,into the ducts of a hydraulic power plant causes the formation ofbubbles in and a rise in temperature of the pressure fluid. This in turncauses an irregular working of the pump delivering the pressure fluidand also a lowering of the eificiency of such a hydraulic power plant.

The removal, and particularly the complete removal of such quantities ofgases, particularly of air present in the pressure fluids has met withgreat difficulties. Various methods and means have been proposed forthis purpose. However, such methods and means have their considerabledrawbacks as they either require additional mechanical means or morespace than is available in many instances.

The invention aims to provide means for degassing or deaerating, ascompletely as possible, the pressure fluid in a hydraulic power plantincluding a pump and a hydraulic motor, and thereby to obtain a quietand regular operation of the pressure pump on the one hand, andsatisfactory efliciency of the pump due to a sufliciently high pressureon the suction-side, on the other hand.

The invention further aims to accomplish the desired result in a verysimple manner in that it provides, in a hydraulic power plant, apressure medium container into which a return pipe from the motor opensand from which a suction pipe to the pump extends.

it is another object of the invention to provide the return pipe fromthe motor to the pressure medium container with a smaller cross-sectionthan the suction pipe from the pressure medium container to the pump.

According to a further object of the invention, the end of the returnpipe is located below the level of the hydraulic fluid in the containerand is formed nozzle-like at a small distance above the preferablyfunnel-shaped, flared entrance end of the suction pipe.

In this manner pressure conditions are created in the pressure mediumcirculation which favorably affect the output of the pressure pump.Simultaneously, the fluid pressure medium will be entirely deaeratedwithin a few minutes owing to the velocity drop of the pressure mediumin the rear of the nozzle-shaped, reduced end of the return pipe.

Further objects and details of the invention will be apparent from thedescription given hereinafter and the accompanying drawing illustratingan embodiment thereof by way of example. In the drawing,

Fig. l is a diagrammatic illustration of the parts of a hydraulic powerplant, and

Fig. 2 is a vertical cross-section of the pressure medium container withthe pipe-ends therein.

Referring now to the drawing, the power plant according to Fig. 1comprises a pump 1 and a hydraulic motor 3 charged by the pump throughthe high pressure pipe or duct 2. From motor 3 the hydraulic fluidwhich, in most instances, will be an oil, flows through a return pipe 4to a fluid container 5 and from the latter through asuction pipe 6 backto the pump 1. Preferably, the return pipe 4 will be introduced into thecontainer 5 vertically from above so as to extend downwardsapproximately half the height of the container in which the fluid level8 is well above the discharge end 9 of the return pipe. Opposite thereturn pipe 4, the entrance end portion of the suction pipe 6 isinserted through the bottom of the container 5 so that there is a shortgap between the ends of the two pipes. Both the return pipe and thesuction pipe may be secured to the top and bottom, respectively, of thecontainer by any suitable means, e.g. by welding or soldering, asindicated at 11 and 12. Means are provided to cause a drop of thevelocity of the current of the hydraulic fluid leaving the pipe 4 beforeit enters the suction pipe 6. For this purpose, the suction pipe 6 isprovided with "a larger cross-section than the return pipe. Furthermore,the end 9 of the pipe 4 will preferably be formed like a nozzle, and theultimate end 10 of the suction pipe will preferably be funnel likeflared. The end 9 of the return pipe and the end It of the suction pipeare secured to each other and held in position by means of bridges orstraps 7, 7' and 7". The container 5 has a filling socket 13 with acover 14 provided with a bore 15 through which the interior of thecontainer permanently communicates with the atmosphere.

In the structure so described, the hydraulic fluid, such as an oil,returning from the motor 3 will be shortly accelerated by thenozzle-shaped end of the return pipe with a subsequent velocity dropbetween the pipe 4 and the flared entrance of the suction pipe 6, whichis wider than the return pipe. In consequence, the gas or air present inthe hydraulic fluid will be expelled in the gap between the two tubesand simultaneously the pressure in the suction pipe 6 and thus in thepump will be favorably affected.

It will be apparent to those skilled in the art that many alterationsand modifications of the structure shown and rhereinbefore described canbe made without departure from the essence and spirit of my inventionwhich for that reason shall not be limited but by the scope of theappended claims.

I claim:

1. In a hydraulic system including a fluid motor having an inlet and adischarge, pump means including a pres sure line arranged to dischargefluid through said motor inlet, and a suction line for said pumpconnected to said fluid motor discharge, the improvement comprising, adegassing device in said suction line, comprising a liquid containerhaving means for maintaining a quantity of liquid therein, a firstportion of said suction line returning from said fluid motor extendinginto said liquid container and terminating in a discharge opening ofreduced dimension from said suction line extending below the liquidlevel in said liquid container, and a second portion of said suctionline having an inlet opening of larger dimension than said dischargeopening and in line with but spaced in an axial direction away from saiddischarge opening in the direction of discharge flow and located in saidliquid, whereby liquid returning through said suction line to said pumpis directed at high velocity from said first portion of said suctionline into the liquid of said container and into said suction line secondportion, the turbulence causing gases to be separated therefrom and torise in said liquid container.

2. In a hydraulic system according to claim I, including bridging means,connecting said first and second portions of said suction line.

3. In a hydraulic system according to claim 1, wherein said firstportion of said suction line is connected into the top of said containerand extends substantially vertically downwardly therefrom, and saidsecond portion is connected into the bottom of said container invertical alignment with said first portion.

4. In a hydraulic system according to claim 1, wherein said secondportion of said suction line inlet opening is flared outwardly.

5. A liquid degassing device for positioning in a return line between ahydraulic motor and a hydraulic pump wherein liquid is forced from themotor to the pump, comprising, a liquid container, a suction return linefor said pump including a first portion extending into said liquidcontainer and terminating in a discharge opening of reduced dimensionfrom said suction line extending below the liquid level in said liquidcontainer, and a second portion of said suction line having an inletopening of larger dimension than said discharge opening and in line'With but spaced in an axial direction away from said discharge openingin the direction of discharge flow and located in said liquid, wherebyliquid returning through 4.- said suction line to said pump is directedat high velocity from said first portion of said suction line into theliquid of said container and into said suction line second portion, theturbulence causing gases to be separated therefrom and to rise in saidliquid container.

6. A liquid degassing device according to claim 5 including vent meansin said liquid container above the liquid level therein. 1 7

References Cited in the file of this patent UNITED STATES PATENTS2,251,664 Davis Aug. 5, 1941 2,571,932 Olsson Oct. 16, 1951 2,668,598Seed Feb. 9, 1954 2,753,011 Downs July 3, 1956 2,765,867 Revallier eta1. Oct. 9, 1956 FOREIGN PATENTS 869,041 Germany Mar. 2,

